Preparation

Download Alpine for Raspberry Pi tarball which is named as alpine-rpi-<version>-armhf.rpi.tar.gz. You will need version 3.2.0 or greater if you have a Raspberry Pi 2.

Mount your SD card to your workstation

Use gnome-disks or fdisk to create a FAT32 partition. If you are using fdisk, the FAT32 partition type is called W95 FAT32 (LBA) and its ID is 0xC.

Mark the newly created partition as bootable and save

Mount the previously created partition

Extract the tarball contents to your FAT32 partition

Unmount the SD Card.

Note: Due to a bug (#7024), you might want to add a "usercfg.txt" file (which is included by config.txt) with enable_uart=1 written in it. Otherwise, the error message "Can't open /dev/ttyS0" will repeatedly be written to the console.

Since Raspberry Pi does not have a clock, the Alpine Linux needs to know what the time is by using a
Network Time Protocol (NTP) daemon. Make sure that you a
NTP daemon installed and running. If you are not sure, then you can install NTP client by running the following
command:

setup-ntp

Busybox NTP client might be the most lightweight solution. Save the changes and reboot, once the NTP software is
installed and running:

lbu commit -d
reboot

After reboot, make sure that the date command outputs the correct date and time.

X11 Setup

Here are what you need if you want to try and run a single X11 application like a browser kiosk or maybe even a desktop: ​

Now commit the changes: (optionally remove the e2fsprogs, but it does contain repair tools)

lbu_commit -d

Remember with this setup, if you install things and you have done this overlay for /usr, you must not commit the 'apk add', otherwise while it boots it will try and install it to memory and not to the persist storage.

If you do want to install something small at boot you can use `apk add` and `lbu commit -d`.

If it is something a bit bigger then you can use `apk add` but then not commit it, it will be persistent (in /user), but do check everything you need is in that directory and not in folders you have not made persistent.

Traditional disk-based (sys) installation

Warning: This isn't yet supported by the Alpine setup scripts for Raspberry Pi. It requires manual intervention, and might break.

It is also possible to switch to a fully disk-based installation: this is not yet formally supported, but can be done somewhat manually. This frees all the memory otherwise needed for the root filesystem, allowing more installed packages.

Split your SD card into two partitions: the FAT32 boot partition described above (in this example it'll be mmcblk0p1) , and a second partition to hold the root filesystem (here it'll be mmcblk0p2). Boot and configure your diskless system as above, then create a root filesystem:

apk add e2fsprogs
mkfs.ext4 /dev/mmcblk0p2

Now do a disk install via a mountpoint. The setup-disk script will give some errors about syslinux/extlinux, but you can ignore these: the Raspberry Pi doesn't need this to boot anyway.

You might also consider overlaytmpfs=yes here, which will cause the underlying SD card root filesystem to be mounted read-only, with an overlayed tmpfs for modifications which will be discarded on shutdown.

Beware, though, that the contents of /boot will be ignored when the Pi boots: it will use the kernel, initramfs, and modloop images from the FAT32 boot partition. To update the kernel, initfs or modules, you will need to manually (generate and) copy these to the boot partition or you could use bind mount so that manually copy the files to boot partition is not needed.